"What are some solid ways to play an “anti-Sicilian” that castles kingside but plays on the queenside?"
There is 2.a3, but it can't be called "solid".
Usually in the Sicilian, White plays on the Kingside... especially without an open d-file.
Maybe you can get some Queenside pressure with the Morra gambit (2.d4 exd4 3.c3), but I don't think the Morra gambit is easy to play, as there's no evident compensation for the pawn (at least, when you don't learn the theory).
Also, you might be interested in reading the following thread : https://www.chess.com/forum/view/chess-openings/suggest-a-good-weapon-against-the-sicilian-66445665
I am not comfortable with how open this leaves the King. What are some solid ways to play an “anti-Sicilian” that castles kingside but plays on the queenside?
Thanks! :)